Field
This disclosure is generally related to efficient communication over a data network. More specifically, this disclosure is related to cut-through forwarding of CCN message fragments using IP encapsulation.
Related Art
The proliferation of the Internet and e-commerce continues to create a vast amount of digital content. Content-centric network (CCN) architectures have been designed to facilitate accessing and processing such digital content. A CCN includes entities, or nodes, such as network clients, forwarders (e.g., routers), and content producers, which communicate with each other by sending “interest” packets for various content items and receiving “content object” packets in return. CCN interests and content objects are identified by their unique names, which are typically hierarchically structured variable length identifiers (HSVLI). Generally, interests and content objects travel through a number of links before they can reach their destination. Each link can have its own maximum transmission unit (MTU), where the differing MTU limits impose different fragmentation requirements. End-to-end CCN fragmentation is described in the following applications:                U.S. patent application Ser. No. 14/065,691, entitled “SYSTEM AND METHOD FOR HASH-BASED FORWARDING OF PACKETS WITH HIERARCHICALLY STRUCTURED VARIABLE-LENGTH IDENTIFIERS,” by inventors Marc E. Mosko and Michael F. Plass, filed 28 Oct. 2013 (hereinafter “U.S. patent application Ser. No. 14/065,691”); and        U.S. patent application Ser. No. 14/067,587, entitled “SYSTEM AND METHOD FOR MINIMUM PATH MTU DISCOVERY IN CONTENT CENTRIC NETWORKS,” by inventor Marc E. Mosko, filed 30 Oct. 2013 (hereinafter “U.S. patent application Ser. No. 14/067,587”);the disclosures of which are herein incorporated by reference in their entirety.        
In a heterogeneous network comprised of both CCN and Internet Protocol (IP) nodes or forwarding devices such as routers, a piece of CCN content (requested in an interest or received in a content object) may be larger than the maximum transmission unit (MTU) of the network. One solution is to use IP at the network layer and rely on IP fragmentation. A CCN message (interest or content object) can be carried as the IP payload and fragmented by currently known IP fragmentation methods as it travels hop by hop to the next CCN router. The CCN nodes can rely on a standard IPv4 or IPv6 protocol stack to reassemble the fragments at each CCN hop. However, this solution introduces delay because the CCN router needs to wait for all the IP fragments to arrive in order to reassemble the entire CCN message and determine the next CCN hop. Furthermore, this solution introduces additional delay because upon reassembly, the IP packet may need to be re-fragmented for subsequent travel across the network.